Different compounds are extracted with different time courses from fruits during microwave hydrodiffusion: examples...

We set out to determine how nutrients diffuse during extraction, using fractional collection. The highest concentrations of sugars (195.5, 64.8 and 60.8g/L, respectively for grape, 'Najbolia' plum and apricot) were found for the earliest stages of extraction, with a decrease in concentration (to 41.4g/L, 48.2g/L and 1.7g/L, respectively) at the end of extraction process. Total polyphenols showed the same trends for plum and apricot (from 4.1g/L to 2.9g/L for 'Najbolia' plum, from 2.2 to 0.2g/L for apricot) but highest concentrations of total polyphenols (for grape and cherry) were obtained at fraction 5 or 6 (out of 7). Carotenoids from cherry tomato also had highest concentrations (at circa 25mg/L) almost at the end of extraction. For volatile molecules from sweet cherry, hexanal, 2-hexenal and linalool had their highest concentrations at fractions 3-4 (out of 7). Diffusion of nutrients depended on fruit destructuring, molecule solubility and localization of the compounds. Fruit size seemed unimportant.